Refrigerating-machine.



`(5. P. CARROLL. REFRIGERATING MACHINE. v A APPLICATION FILED DEC. 3, 1910. RENEWED AUG. 9, 1916. 1,219,534.. Patented Mar. 20, 1917.

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UNITED STATES PATENT oFFIoE.

. GEORGE CARROLL, OF BRIDGEPORT,CONNECTICUT. y

REFRIGERATING-MAGHINE'. j

Specification df Letters Patent.

Patented Mal'. 20, 1917'.

AApplication l'eidvDe'cember 3, 1910, Serial No. 595,453'. Renewed August 9, 1916. Serial No.`v114,069.

To all whom it may concern:

Be it knownthat I, GEORGE P. CARROLL,

- of an inch or more, leadsdown'ward through a citizen of the United States, and a residentl of Bridgeport, Fairfield county, State of Connecticut, have invented a new and useful Refrigerating-Machine, of which the following is a specification. 4

- My invention relates to improvements in refrigerating' machines of the absorption type. My purpose is to construct an autov12, opening downward and havingavertical 'stem 13 extending upward through' the cas-v ing. The inlet ndof the coil 4 leads from the matic machine of the -intermittent subtype such that, until the supply of refrigerant in refrigerant reservoir shall have been practically exhausted, a refrigerator thermostat shall control the flow of refrigerant through the expansion coils into. the stilland the flow of cooling water to the still then acting as an absorber; such that, upon i such exhaustion, the flow of refrigerant through the expansion coils and of water to the still shall cease and a heating of the still shall begin; such that upon reaching a predetermined limit the heating of 'the still shall cease and the control of the machine shall be restored to the refrigeratorA thermostat; such that any approved means maybe employed for condensing the gaseous refrigerant driven off from the still into the refrigerant reservoir; and such that, if during any heating anexcessive pressure shall accidentally develop, the heating of the still shall thereupon terminate. My invention includes means for accomplishing these purposes. There are alsodetail iin--v p'rovements as will appear. The means employed are as will appear. p i In the drawings the ligure 1s a diagramy matic representation of my invention.-

An 'inclosed horizontal cylindrical condenser tank 1k has on top, near its right end,

` an inlet and an elbow 2 lfor the admission of -heated ammonia gas; and has at the bottom, near its left 'en d, an outlet for condensed gas, leading into 'theupper end of a much smaller liquid ammonia receiver 3, which declines toward its outlet end. A cooling water coil4 enters the head forming the left end of the tank 1, 'near the bottom,

vcoils upm-'ard throughl the tank, and emerges through .thexhead near. the top of the tank. A small hand valve4 5 is connected' with 'the upper side of the elbow 2 andA serves as ma vacuum valve, oras a charging valve, or as a purge valve, as occasion requires. Connected with the top of the tank 1, near the elbow 2,'is a high pressure gage 6. rom

the outlet end ofgthereceiver 3 a liquid pipe 7, ofan internal diameterof three quarters the VItop of a refrigerator 8.

From a T 9, connected with a sourceof cool water supply, a pipe 10 leads to an inlet at the bottom of the casingll of a condenser water valve. Above theinlet of ,the-

casing 11, and disposed toward it, is a valve seat adapted for :the seatingv of a flat valve right of the casing 11, above its 'valve seat'. c helical compression spring 14l surrounds'the stem. 13, above the casing 11 and abuts at its` top against the under side of a collar v15 surrounding the stem. By this meansthe spring 14 tends to lift the valve- 12 so as lto close the valve., A bracket 1G is bolt- -ed to the casing 11 and supports a verticalsolenoid 17,- havinga core 18 secured to the veXtreme top ofthe stem 13. The solenoid reciprocate vthrough an opening in apartpf the bracket 1G and when the valve 12 1s closed, as shown, rests against the upper end of the core 18; but when the valve 12 is opened, in consequence ofthe e'nergiza.-v

tion ofthe solenoid 17, the arm is adapted to slide to the right over the top of the' c'ore 18-so' as to lock the valvevin an open posi- 22, surrounding the left stem end of the inside `of the yoke referred to and at its right end against a collar on the stem in such a way as to tend to thrust the arm 21 -into its locking position.- But the solenoid 19 is so wound that, when it is energized, it overcomes the thrust of the spring 22 and draws the arm 21 to the left out of the way of the core 18.

A T` 23 is connected to the outlet -end of v the coil 4. An angle tube 24, open at its upper outerend 'and closed at its inner lower euch-occupies a part of the coil 4 v tion. A light helical compression'spring` y v,core 20, abutsat its left end against the\ within the upper left part ofthe tank 1 Y and extends upward and outwardthrough the 'l' 28. Surrounding and` flaring outward from the open upper end of the tube 24 is a flanged casing 25, inclosed on top by a somewhat flexible diaphragm 26. The thermostatic chamber, composed of the parts 24, 25 and 26, contains a fluid vapor-izing at the usual atmospheric temperatures, belng preferably anhydrous ammonia with enough liquid to fill that part of the tube 24 within the coil 4. A motor rod 27 has a flanged. footresting onthe -upper center of the diaphragm 26 and is surrounded just above its foot by a helical outward opposing spring 28. A skeleton top 29, having a perforated and internally threaded central hub around the rod 27, is over the spring 28 and at its outside circumferential rim clamps the .diaphragm 26 to the casing 25. A threaded nut 30 surrounds the rod 27 above the spring 28 and screws up or down in the hub of the top 29. By means of the nut 30 the thrust of the spring 28 and consequently the outward movement of the diaphragm 26 vare regulated as may be desired. The part of the rod 27 above the top 29 is of reduced diameter and is surrounded by an independently supported collar 31. A light helical `inward opposing spring 32'surrounds` the rod,27 just above the collar 31. Threaded on to the rod 27 just above the spring 32 is an adjusting nut 38, `by means of which the thrust of the spring 82 and consequently the inward movement of the diaphragm 2G are regulated as may be desired. Secured to the eXtreme top of the rod 27 is a horizontal motor arm 84, extending to the left. The parts 24 to v34 inclusive are-sufficient to constitute a condenser thermostat.

Supported upon but insulated from a bracket 35, bolted to the top 29, are a lower stationary switch arm 3G and a lower spring switch arm 87. The arln 87 is under the left end of the arm 34 and is above and initially out of Contact with the arm 36; but, when the arm 34 is moved a sufficient distance downward, the arm 34 overcomes the spring of the arm 37 and forces the latter into electric Contact with the arm 8G.

wires 40 and 41 lead respectively to andfrom a source of electric energy'42. A wire 43 leads from the wire 40 and branches to the arms 37 and 39. A wire 44 leads from the arm 89 to the solenoid 17. A wire 45 leads from the solenoid 17 to t-he wire 41.

A Wire 46" leads from the arm 36 to the lsolenoid 19, and a Wire 47 leads from the seat.. Suitably supported in the upper part of the refrigerator 8 is an open top tank 49, adapted to be nearly filled with calcium chlorid brine, occupying the refrigerator from back to front, but having, between itself and the side walls of the refrigerator,

.a free passage at the right for the ascending warmer air and a free passage at the left, of the samelor a little more width, for the descending chilled air. The right wall 50 of the tank'49 extends upward above the rest of the tank so as to leave, between the top 'of the wall and the cover of the refrigerator 8, a passage equal to the passage at the right of the tank. An expansion coil 51 leads from the valve 48, just above the main part of the tank 49, coils downward through the tank and passes outward, with a slight decline, through the side walls of the tank and of the refrigerator 8.

A tube 52, open at its upper outer end and closed at its inner lower end, for most of its length occupies the ascending air space in the refrigerator 8, but extends up through the cover of the refrigerator. Surrounding and flaring outward from the open upper end of the tube is a flanged casing- 53, inclosed on top by a somewhat flexible diaphragm 54. The thermostatic chamber, composed of the parts 52, 53 and 54, contains a fluid vaporizing at the usual refrigerator temperatures, being preferably anhydrous ammonia with enough liquid to more or less fill that part of the tube 52 within the refrigerator 8. A motor rod 55 has a flanged foot resting on the upper center of the diaphragm 54 and is surrounded just above its foot by a helical. outward opposing spring 5G. A skeleton top 57, having a perforated and internally threaded central hub around the rod 55,-is over the spring 50 and at its outside circumferential rim clamps the diaphragm 54 to the casing 58, A threaded nut 58 surrounds therod 55 above the spring 5G and screws up ordown in the hub of the top 57. B v means of the nut 58 the thrust ofthe spring 5G and consequently the outward movement of the diaphragm 54 are regulated as may be desired. The part of the rod above the top 57 is of reduced diameter and is surrounded by an independently supported collar 59. .A'light helical inward opposing spring 69 surrounds l the rod 55 just above the collar 59. Thread ed on to the rod 55 just above the spring 60 is an adjusting nut 61, by means of which the thrust of the spring 60 and consequently the inward movement of the diaphragm 54 are regulated as may be desired. Secured to the extreme top of the rod 55 is a horizontal motor rod 62, extending to the right. The parts 52 to G2 inclusive are suflicient to constitute a refrigerator thermostat.

Supported upon but insulated from a bracket 63, bolted to the top 57, are a lower stationary switch arm 64 anda lower'spring switch arm G5. The arm 65 is under the right end of the arm 62 and is above and initially out of contact with the arm 64:; but, when the arm G2 is moved a sufficient distance downward, the arm 62 overcomes the spring of L.thearm (35 and forces the latter into electric contact with the arm 64. Also supported upon but `insulated from the bracket G3 are an upper stationary switch arm 66 and an upper spring switch arm,67. The arm (i7 is over theright endof the arm 62 and is underand initially out of Contact with vthe arm 66; but, when the arm 62 is moved a sufficient distance upward, the arm 62 overcomes the spring of the'arm 67 and -forces the latter into electric contact with the arm 66.

A switch contact 68 issupp'orted by but is insulated from a double solenoid support 69 andis connected with the wire 40. A

4 switch 70 at one end is pivoted upon but is insulated from the support 69"and at its other end is adapted to. make or break connection with the contact 68. Supported on the support 69 at the left of the switch 7 O is Y a horizontal left solenoid 71 and at the right port 69 to which the switch 70 is pivote'd, a'

of the switch isa horizontal right solenoid 72. ommon to the solenoids 71 and 72 is a double end core 73 pivotally connected with the middle of the vswitch 70, so that when the solenoid 72 isA energized the core pulled to the right to close the switch, as`

shown, and when the solenoid 71 is energized the core is pulled to the left to open the switch. F rom the insulated part of the supwire 74 leadsand branches to the arms 65 and G7.

A vertical cylindrical shell 75,A adapted to contain aqua ammonia by a construction more fully explained later, has, within its curved bottom, an electric heating member 7G, containing high resistance wires 77,

Through the member 7G are numerous verti doubly wound, so as to be non-inductive.

cal openings 78, so that heat from the wires -mav be readily transmitted to the contents of the shell 75, The member 7 6 is also surrounded by a free space on-allv sides except that itl has a' stem 79 passing through the bottom of thev shell 75. Formed on the outside of the shell 75 is astufling'boxO, containing an annular packing 81 around the v4stem 79. A stuiling gland 82 surrounds the stem 79 and is screwed into the stutng box 8O so as to compress the packing S1. By this means leakage is prevented around the stemv 7.9. A feed wire 83 leads to the wires 77 through the stem 79-and a return wire 8l leads from them through the stem to the wire 41. 4

It is to be understoodthat, owing to the strong corrosive effect of ammonia, neither copper nor any of its alloys are to come in contact with ammonia, whether anhydrous or in solution. Consequently the wires 77 are inclosed in the members 7G, made of ir'on or'steel and glass enameled in the manner to be described, and are surrounded within the member by heat transmitting material such as is usual in electric heaters.

Passing through the side ofthe shell 75 is a gas inlet pipe 85', with a slight inward decline, ending in thev upper end of a vertical pipe 86', having a very widely Haring discharge end immediately above the mem- `ber 76. A hand valve S7, outside the shell 75, may be used, on occasion, to shut oliC the pipe 85. Also passing through the side of the pipe 86 and emerging from the side of the shell a little distance above the member 7 6. A cover S9 is secured tothe iianged top of the 4shell 75.

An expansion coil outlet vvalve structure 90 has the inlet of its lower casing 91 con- 'A nected with the outside and lower end of the coil 51 and has thel outlet of its lower casing .connected with the inlet end of a slightly `descending pipe 92, coupled to the inlet end of the pipe S5. The course through the casing 91 is downward; and between its inlet and outlet isw a valve seat adapted for the seating of a iat valve 93, opening downward toward the outlet of the casing vrand having a vertical stem v94. extending upward toward the top` of the casing." The upper endo the stem 94 is secured `to the center of a somewhat iiexible diapl'iragm 95,l which has an inside 'exposed surface 'a little larger than v92-tends to so close the valve 93, the tendency 'to close increasing as the back pressure increases. It will be further noted that the downward course of the refrigerant from the shell 75, above the pipe 85, is the inlet I end of a helical cooling coil 8S, surrounding the elbow 2 to the end of thepipe 86 is pocketless.

Bolted to the top of the casing 96v is a solenoid yoke 97 holding in place, supported upon the casing, a verticalsolenoid 98. A

core 99 is adapted to reciprocate within the` solenoid 98, has a lower stem extension passing through an opening in the top of the casing 96 and secured to the top of the diaphragm 95, and has an upper stem extension passing through an openingA .in the top of' .theI yoke 97 and threaded at its upper end.

A helical compression spring/100 surrounds the upper stenrextensio'n of the core 99, above the yoke 97, and abuts at its top against the under side of a collar 101 threaded on to the extension. By this means the spring 100 adds force to the diaphragm 95 in tending to lift the valve 93 and its tendency in so doing can be regulated by`the collar 101. The solenoid498 is so wound that when it is energized it overcomes the diaphragm 95 and the spring 100 and lowers the valve 93 so as to openlthe valve. A horizontal cross arm 102 is secured to theex has a left stem extension passing through the\ left end of the yoke. A helical compression' spring 100 surrounds the left stem extension of the core 105 to the right of the left end of the yoke 103 and at its right abuts against a collar on the extension. When the valve 93 is elevated, as shown,the eXtreme right vend o1 the right stemextension of the core 105 abuts against the left end of the arm 102, as shown; when an energization of the solenoid 98 depresses the valve 93, ythe spring 100 forces the` extreme right end of the right stem extension of the core 105 over the arm 102 so as to lock the valve in an open position after the energization of the solenoid 98 has ceased; the solenoid 104 is so wound that, when it is energized, it overcomes the spring 10G so as to draw the core 105 to the lett, releasing the arm 102 and permitting the spring 100 to close the valve; and linally, when the solenoid 101 is no longer energized, the spring 10G'iforces the core 105 into its initial position. From the arm G6 a wire 107 leads tol the solenoid 98; and from this solenoid a wire 108 leads to the wire 11. From the arm 611 a wire 109 leads to the solenoid 101; and from this solenoid a wire 110 leads to the wire 108.

A branch water pipe 111 leads from the T 9 to an inlet at the bottom of the casing 112 of a water inlet valve, to the right of the valve structure 90. Above `the inlet of the casing 112, and disposed toward it, is a valve seat adapted for the seating of a flat valve 113, opening downward and having a vertical stem 114 extending upward through the valve casing. A pipe 115 leads from the right of the casing 112, above its valve seat, slightly descends and is coupled to the inlet end of the coil 88. A helical compression spring 11G surrounds the stem 111 above the -casing 112 and abuts at its top against the and when the arm 102 is lifted, the spring 116 lifts the valve 113 andcloses the valve A double solenoid support 120 supports a switch contact 121, connected with the wire 40,-an`d an opposite switch contact 122, connected with the wire 83, both contactslbeing insulated from the support. Supported on the support 120 at the left ot the contacts 121 and 122 is a horizontal lett solenoid 123 and at the right ol these contacts is a horizontal right solenoid 121. Common to the solenoids` 123 and 124 is a double end core'125, carrying a cross bar switc-h126, which makes contact with the contacts 121 and 122 when the solenoid 123 is energized and breaks contact with them, as shown, when the solenoid 124e is energized.

A thermostatic tube 127, open at its upper end and closed at its lower end, projects downward through the cover 89 so tar into the shell 75 that, for a part of its length, while the machine is in operation, the tube willbe immersed in the aqua ammonia contained in the still. Surrounding and flaring outward from the open upper end of the tube 127 is a flanged casing 128, inclosed on top by a somewhat liexi'ble diaphragm 129. The thermostatic chamber, composed of the parts 127, 128 and 129,'contains an expansive fluid', preferably ethyl chlorid which vap'orizes at about 54 F. Afmotor rod 130 has a 1 anged foot resting on the upper center of -the diaphragm 129 and is surrounded just above its foot by a helical outward opposing` spring 131. A skeleton top 132, lhaving a perforated and internally threaded central hub around the rod 130, is over the spring l131 and at its outside circumferential rim clamps the diaphragm 129 to the casing 128. A threaded nut 133 surrounds the rod 130 above the spring 131 and screws up or down in the hub of the top 132. By means of the lett.

nut 133 the thrust of the spring 131 and consequently the outward movement of the diaphragm 129 are regulated as maybe desired. The part of the rod 130 above the top 132 is of reduced diameter and is surrounded by anindependently supported collar 134. A light helical inward opposing spring 135 surrounds the rod 130 just above the collar 134. Adj ustably threaded on to the-extreme top of the rod 130 is a horizontal cross arm By adjusting the longitudinal position of the arm 136 the thrust of the spring 1.35 .and consequently the inward movement of the diaphragm 129 are regulated as may be desired. yThe parts 127 to 136 inclusive are sufficient to consti- Itute a still thermostat.

A high pressure pipe; 137,I leadsv outward and upward from the upper part of the s hell 75 into the bottom of a flanged casing 3138, inclosed on top by a somewhat flexible diaphragm 139. A motor rod 140 has a flanged toot resting on the upper center of the diaf phragm 139 and is surrounded just above its foot by a helical outward opposing spring 141. A skeleton top 142,v having a perfo- Irated and/internally threaded hub around the rod 140, is over the spring 141 and at its outward circumferential rim clamps the diaphragm 139-to the casing 138. A threaded nut-143 surrounds lthe rod 140 above the spring 141 and screws up or down in the hub of the top 142. By means of the nut 143 the thrustof the, spring 141 and consequently the outward movement of the diaphragm 139 are regulated asmay be desired. Adv justably threaded on to the extreme top of the rod 140 is a horizontalv cross arm 144, extending to the left and almost to the right end ot the arm 136. The parts 137 to 144 inclusive are sufiicient to constitute a high pressure safety device. l

A suitably supported vertical sleeve 145 has within it a reciprocating motor rod 146,

having at its lower end a disk immediately over the adjacent ends of the arms 136 and 144. A light helical spring 147 surrounds the rod 146 above its disk and below the sleeve 145 so as to cause the rod to follow the arms 136 and 144 on a downward movement by them. Adjustabl-y threaded on to the extreme top of the rod 146 is a horizontal motor arm 148, extending to the Supported upon but insulated from a bracket 1ML/integral with the sleeve 145, are a lower stationary switch arm 150 and a lower spring switch arm 151. The arm 151 is under the lett endet the arm 148 and is above and initially cut out of `contact with the arm 150; but, when the arm 148 is moved a sutlicient distance downward, the arm 148 overcomes the spring ot the arm 151 and forces the latter into electric are an upper stationary switch arm 152and an upper spring switch arm 153. The arm 153 is over the lett end ot the arm 148 and is under and initially out of contact with the arm 152; but, when .the arm 148 is moved a sufiicient distance upwardfthe arm 148 overcomes the spring of 'the arm 153 and forces the latterv into uelectricfcontact with the arm 152. A wire 154 leads Jfrom Vthe wire 40 and branches tothe arms 151 A wire 155 leads from the arm' `solenoid 72; and from thisv solenoid awire 158 leadsVv to the wire 41.

11 T 159 is connected with the outside lower end of the coil 88. From the under -side of the T 159 a pipe 160 leadsl to a T 161. A hand valve 162 controls the pipe 160 and is used to determine the quantity ot tlow through the coil 88 when the valve 112 is open, the idea being to let the water scarcely more than trickle from lthe coil. From the T161 a pipe 163 leads to an outlet T 164, connected'with'the waste.

lThe upper part of the casing 165 of a water outlet valve is connected with the T 159 as an inlet and the lower part of the casing is connected with the T 161`|as an outlet. Between the inlet and outlet-ot the casing 165 and disposed toward the outlet, is a valve seat adapted for the seating ot a flat valve 4166, opening downward and having a vertical stem .167 extending upward through the valve casing Bolted to the -top of the casing 165 is a solenoid yoke 168-, holding in place, supported upon the casing, a vertical solenoid 169. A core 170 is adapted to reciprocate within'the solenoid 169. is-secured to the topvof the stem 167,

land has `an upper, stem extension passingthrough an opening'in the top of the yoke 168, -with a catch disk 171 secured to its top. A helical compression spring 172 surrounds the upperstem extension of the core 170, above the' yoke 168, and abuts at its top on the under sideot a collar 173 surrounding the extension under the valve 171. The spring 172, actingon the collar 173, tends to lift the core 170, the stem 167 and the valye 166v so as to close the valve. But the solenoid 169 is so wound that when it is energized, acting on the core 170, it overcomes the spring 172 and opens the valve 166. Supported by a bracket vextending from the yoke 168 is a solenoid yoke 174, supportinga horizontal solenoid 175. A core 176 is adapted to reciprocate within the solenoid 175, has a right stem extension passing through the right end of the yoke 174, and has a left stem extension passing through the lett end oit the yoke. A helical compression spring 177 surrounds the right stem extension 'of the core 176 to the left of the right end of the yoke 17-l and at its lett end abuts against a collar on the extension. 'hen the valve 166 is elevated, as shown, in which case the valve is closed, the eXtreme lett end oi the let't stem extension of the core 176 abuts against the valve,` as shown; when an energization ofthe solenoid 169 depresses the valve 166, the spring 177 forces the extreme lett end ot' the core 176 over the disk 171 so as to lock the valve in an open position after the energization ot the solenoid 169 has ceased; the solenoid 17 5 is so wound that, when it is energized, it overcomes the spring 177 so as to draw the core 176 to the right, releasing the disk 171 and permitting thespring 172 to close the valve; and finally, when the solenoid 175 is no longer energized, the spring 177 forces the core 176 into its initial position. A wire 178 leads from the wire 157 to the solenoid 175. A wire 179 leads from the solenoid 175 and joins a wire,180 which leads froml the solenoid 169 to the wire 41. Threaded into an opening in the cover 89 is the lower member 181 of a check valve casing having an outwardly disposed valve seat. Seated on the valve seat of the member 181 is a check valve 182, opening outward and upward and having an upwardly extending stem surrounded by ayery light helical spring 188. The upper member 181 of the valve casing bears upon the top of the spring 188, has an opening which the stem of the valve 182 occupies so loosely as to leave sutlicient space for ascending gas, and at its iianged lower edge is bolted to the member 181.- hand 'alve casing 185 is threaded on to the member 181, has a coupling thread around its upper end and is provided with a hand valve 186. By` means of the valves 87 and 186 the still may be shut olic -trom the rest of the machine, it occasion so requires. Coupled to the casing 185 is an upwardly ascending pipe and elbow connection 187. Slightly asceilding from the elbow end of the connection 187 is a pipe 188 which leads into the elbow 2. Just as there is a pocketless downward course from the `elbow 2 through the expansion chamber into the shell 75, so there is a pocketless upward course from the shell 75, for ascending gas, into the elbow. Consequently there is no place in the machine for the lodgment of entrained water. From the lla Q8 a pipe 189 leads into the higher end of a cylindrical casing 190' surrounding the pipe 188, the place of 011-.- trance, being` near the elbow From the lower end of the casing 196, near the connection 187, a pipe 191 leads to the "l" 161 and is provided with a hand valve 19:2 which is used to determine the quantity of tlow through the coil l. The pipe 188 and the casingl 190 are sullicient to constitute a dehydrater., although it is more` usual 'to arrange the parts so that the, descending water will low through the inner pipe yand the ascending gas will pass through the outer annular space.

Connected with the top of the tank 1 is a flanged casing 193, inclosed on top by a somewhat flexible diaphragm 191. A motor rod 195 has a flanged foot resting onthe upper center of the diaphragm 191 and is surrounded just above its foot by a helical outward opposing spring 196. A skeleton top 197, having a perforated and internally threaded hub around the rod 195, is over the spring 196 and at its outside circumferential rim clamps the diaphragm 191 to the casing 198. A threaded nut 198 surrounds the rod 195 above the spring 196. and screws up or vdown in the hub ot the top 197. By means oi the nut 198 the thrust ol? the spring 196 and consequently the inward movement of the diaphragm 194 are regulated as maybe desired. djustably threaded 011 to the eX- treme top of the rod 195 is a horizontal cross arm 199, extending to the right. 'llhe parts 193 to 199 inclusive are sufficient to constitute a starter.

Supported upon but insulated from a bracket 200, bolted to the top 197 are a'stationary switch arm 201 and va spring switch arm Q02. rlhe arm 202 is under the right end of the arm 199 and is above and initially out of contact with the arm 201; but, when the arm 199 is moved a suliicient distance downward, the arm 199 overcomes the spring ot the arm 202 and forces the latter into electric Contact with the arm 201. From the wire ll0 a wire 203 leads to the arm 202. Frein the contact 201 a wire 201- leads to the solenoid 169. From the wire 201 a wire Q05 leads to the solenoid 71; and from this solenoid a wire 206 leads to the wire 41. From the wire 201 a wire 207 leads to the wire 109. From the wire Q04 a wire 208 leads to the solenoid 128; and from this solenoid a wire 209 leads to the wire 41. A

A thermometer 210 extends downward through the cover 89 so as to have its lower end immersed in the aqua ammonia in the still.

rlhe method of operation is as follows: A back gage pressure of 15 lbs. denotes a temperature of OO F. in an expansion coil. But in a refrigerator 8, of the character indicated, so low a temperature in the coil 51 would probably not be desired. llence the absorption in the shell 75 will take place uuder a back pressure in excess of 15 lbs. But under a pressure oil 15 lbs. a solution ot aqua ammonia can contain S8 per cent. by weight of ammonia up to a temperature ot .lOl-O l". Flence enough distilled water is introducedv into the shell 75. through the valve 5 or pret# erably through a closable opening in the cover 89, so that` when the water reeei ves enough ammonia 'tov form a per cent. solution, the shell will be about fourlifths full. The valves 87 and 186 being open, the y' quantity of anhydrousammonia.v is then slowly introduced through the valve 5 sufii cient-'to make lthe 38 percent. solution when alll of the ammonia sh'all eventually reach the shell75. The advancing ammonia creates aipressurein the coil 51 that closes the valve-48. .The .bulk ofthe ammonia then occupies the receiver 3, the pipe 7 and the valve 48 in advance of its seat. `Ammonia vapor also presses the'valve 182 more closely lto its seat. {After the machine'has been al lowed to stand `fora while, the residual. air

-rises to the top andmay be purged off through the -val-ve 5.

Various adjustments are made as follows: The spring 28 is so'adj'usted that the arm 34 will force' the' 'arm 39 into contact-with the arm 38 when the ammonia pressurein the thermostatic chamber of the parts 24,

25 and 26 rises say to 183 lbs.,.as indicated by the gage 6, corresponding to a tempera-A turein the coil 4 O15-'95". `And the spring 32 is so adj'ustedthat the arm 34 will force the arm 37 into Contact; with the arm 36 when the pressure in that chamber falls sayto 139 lbs., as Vindicated by the Agage 6,F

corresponding to a temperature of 80o in into contact with the arm101 when the pressure in the tank 1 drops say to 30 lbs.

The pressure limit of 30 lbs. is' taken because, with a proper initial charge of am! monia, the water in the 'shell 75 would continue to absorb ammonia until the pressure in the tank 1 had dropped to and below that limit. The valve 48 is so adjusted as to prevent a pressure in excess say of 25 lbs. in the coil 51. This pressure corresponds toa vaporizing tepiperature in the coil of 12O and will produce a temperature in the brine tank of only a few degrees higher. Assume the temperature to be maintained in the refrigerator 8 is to be between the limits of 35o and38". Then the spring 56 is so adjusted that the arm 62 will force the arm 67 into contactnvith the arm 66 when the ammonia pressure in the thermostatic chamber of the parts 52, 53 and 54 risesl to 55 lbs., correspondingto a temperature of 380. And the spring 60 is so'adjusted that the arm 62 will force the larm 65 into contact with the 'arm 64 when the pressure in that chamber falls to 51 lbs., corresponding to a temperature of 350. Also the spring 131 is so "8 drops to 350.

adjusted-that the arms 136 and 148 will force the arm 153 into contact with the arm 152when the'iu-id pressure in the thermostatic chamber of the parts127, 128 and 129 'rises' to a Vpressure corresponding say to a temperature of 280O in the still. And ythe spring 135 is so adjusted that the spring 147 will'cause the arm 148 to force the arm 151 into contact with the arm150 when the lluid pressure in that chamber falls to a pressure' corresponding say tol a temperature of 1100 in thestill. Itis not-necessary to. know what t lwill be-these two pressure'limitsof the fluidy vapor.' For tli e `proper spring` adjustments to produce thetwo actions ofvthe arm 148 are determined by trial at the two temperature limits in the still', as observed by the thermom'eter 210. And"the"spring 141 is so adjusted that the arms 144'and 148 will force the arm f 153into `contact with thev arm .152'

when, it so happens, still rises say to 220 lbs.

Now assume that water lis` free to iow the pressure in the ,through the, T 9, thatfacurrent 'frein the wires 40 and "41 is available, and that the temperature -in the refrigeriitor '8 rises to 380. .Thereupon the arm62 forces the arm 67 'into Contact 'with 4the 'arm 66and' a'cur- -rent passes from th'e wire 40 lthrough the .parts 68,70, 74, 6 7, 6.6, 107,- 98and 108 back to the wire'41.` The consequent energization of the solenoid 98 Aopen s the valves 93 and 113. The ammonia` gas in the coil 51 now .passes through'the valve 93 andthe pipes 92, 85 and l86 and,isyab'sorbed by the water the shell-7 yIfiqui'd ammonia' passes ljthe valve 48, *vaporizes in the coil 5 1 and the coil. Also the spring 196 is so'adjusted. that the arm 199 will force the arm 1,02'

Cools` .the brine. Tater liowsth'rough the pipe 111, the valve 113 and the pipe' 1154 into the coil 88 and passes out through the T 159, the pipe`1-'60, the T161, the p ipe'.163

and the T 164. The How of waterthrough the .coil 51 to the outside of the tank 49. The

chilled air over` the tank 49desejends within the refrigerator 8 along' the inside of its left wall and the warmer lair rises past the tube 52over the wall50. "rlWhthe vfall of f temperature thearm62 drops and the arm 67 springs away from the arm 66. Aftera while the temperature in the refrigerator Thereupon the arm 62 forces-the arm into contact with the arm 64 and a current passes from thewire 40 through the parts 68, 70, 74,65, 64, 109, 104, 110 and 108 back to the .wire 41. The consequent cnergization of the solenoid 1 04 draws the core 105 to the left and the valves 93 and 113 close. Vith the closing of the valve 93 pressurev accumulates in theV coil 51 and closes the valve 48,. The brine in the tank 49 keeps the refrigerator cool for-some hours after the Vaporization'of ammonia through the Valve 48 has ceased.

These cycles of opening and closing of the rali-es 93 and 113 continue as long as any liquid ammonia remains in the refrigerant reservoir. As the last of lthe liquid passes through the valve 48, vaporization takes place in advance of the valve seat. But as the pipe 7 is several inches long and of the.

diameter stated, the refrigerating eifect is produced within the refrigerator 8, rather than outside of it. While any liquid remains in the refrigerant reservoir, the pressure in the starter is precisely that which corresponds to the temperature outside of the pipe 7 at its coldest part; and, in the condition assumed of an operation of the maehine'to maintain a low temperature limit of 35D in the refrigerator 8, the pressure remains above 51 lbs. But, just after the last of the liquid ammonia has passed through the valve 48, the ammonia in the refrigerant reservoir no longer is a vapor but is a gas. As a gas the pressure of this ammonia deponds upon its density exclusively. The passage of. seine of this gas through the valve 48 diminishes the density and pressure of the remaining gas in the refrigerant reservoir until finally the pressure in the starter drops to 30 lbs. Thereupon the arm 199 forces the arm 202 into contact with the arni 201. A current now passes from the wire 40 through 'the parts 203, 202, 201 and the wire 204 by several branches back to the' wire 41. One branch current from the wire 204 passes through the parts 205, 71 and 20G. The consequent energization of the solenoid 71 opens tlie switch 70 and makes the refrigerator thermostat inoperative for the time being. Another branch current passes from the wire 204 through the parts 207, 109, 104,v 110 and 108 back 'to the wire 41. The consequent energization of the solenoid 104 d aws the core 105 to the left so as to close the valves 93 and 113 if they are open. Another branch current passes from the wire 204 through the parts 208e 123 and 209. The consequent energization of the solenoid 123 closes the switch 126 and permits the passage of a current from the wire 40 through the parts 121, 120, 122, 83, 77 and 84 back to the wire 41. The member. 70 being' thus heated, the heating of the contents of the shell 75 begins. And another branch current passes from the wire 204 through the parts 169 and 180 back to the wire 41. The consequent energization of the solenoid 169 opens the valve 160 and lets the water flow from the coil 88 more rapidly than it could flow through the valve 102 alone.

iis the contents of the shell is heated ammonia gas is driven olif, overcoming the slight resistance of the valve 182, and passes through'the parts 181, 184, 187, 188 and 2 into the tank 1. 1t will be noted that as the condenser pressure rises, the arm 199 moves upward' and the arm 202 breaks contact with the arm 201. This isas it should be, for the starter has completed its work. The heated gas in the tank 1 soon raises the temperature of the .water in the coil 4 to 950. Thereupon the arm 34 forces the arm 39 into contact with the arm 38. And a current then passes from the wire 40 through the parts 43, 39, 38, 44, 17 and 45 back to the wire 41. The consequent energization of the solenoid 17. opens the valve 12 and permits water to flow through the parts 4, 1891 190, 191, 192 and 164.V The water flowing in the coil 4 condenses and liqueies the ammonia coming into the tank 14 and the 'ater `flowing downward in the casing 190 cools the ascending ammonia to such an extent that nearly all of theentraincd water vapor is condensed and flows back as w'ater into the shell 75. 4As fast as it is condensed, the liquefied ammonia drops to the bottom of the refrigerant reservoir. The valve 11 continues open until the temperature. in the coil 4 drops to 800. Thereupon the arm 34 forces the arm 37 into contact 'with the arm 36. And a current then passes from the wire 40 through the parts 43, 37, 36, 40, 19, 47 and 45 back to the wire 41. The consequent energization of the solenoid 19 draws the arm 21 to the left and the valve 12 closes. The closing ofthe valve 12 may not take place until after the heating` of the shell 75 has terminated or it may occur several times in each heating. Furthermore if the atmospheric temperature rises above 95", the valve 12 may7 operate at any time. It will thus beA seen that the automatic condenser,

that is shown and described, is entirely independent in its operation of the other parts of the machlne.

Under the conditions assumed the heating Iof the shell 7 5 normally continues until its temperature reaches 2800. At that temperature, the percentage of ammonia in the so! lution in the shell 75, which at the beginning of the heating was 38 per cent., is reduced to about 20 per cent., if the temperature in the tank 1 is at 950, which corresponds to a head pressure of 184 lbs., as indicated by the gage G. Or thc percentage of ammonia in the solution is reduced to about 1G per cent., if the temperature in the condenser is at G, which corresponds to a head pressure of 140 lbs. as indicated by the gage (5. 0r the percentage of ammonia in the solution is reduced to some percentage between 10 and 20, if the temperature of the still reaches 280o when the temperature in the condenser is at some point between 80O and 95o. 1u any such case. however` at the limitof 2800, the arms 130 and 148 force the arm 153 into contae"y with the arm 152. lArnd a current then passes from the wire 40 through the parts 151, 153, 152, 155,124 and' 156 back to the;

' pressure of 168 lbs. as indicated by the gage 6. The only disadvantage in lowering the opening limit of the valve 121s that, with this. type of automatic condenser, there will be a greater. iow of water in summer weather ranging above 90o. So also the percentage of ammonia remaining in the solution at the normal end of the heating may limit to be some higher limit than 2800, say 3000. A113000, with a head pressure of 184 lbs., corresponding to 95o, the percentage of ammonia in the solution is reduced lto about be much reduced by making the heating 15 per cent.; with a. head pressure of 168 lbs., corresponding to 900, such percentage is reduced to about 14 per cent.; and with a head pressure of 140'lbs., corresponding to 800, such percentage is reduced to about 11 per cent. Of course a higher heating limit would be 218 requires more fuel and an increased amount of water vapor is driven over, most of .it indeed comingback through the dehydrater, but some of 1t passing into the refrigerant reservoir and coming back through the coil 51. y

Sometimes by accident 'there is a failure of condensing water. With a very slow heating of the contents of thev shell 75, too slow for practical purposes, the ammonia driven off from the shell might give off its heat in the tank 1 by radiation and so become liquefied. 4But with a heating of the contents'of the shell 75 at the usual rate of increase of'the heat, a failure of condensing water results in a. quick rise .of temperature in thetank 1 and of--pressure inall the passages reaching back to the shell 75. If the temperature ofthe liquid ammonia in the refrigerant reservoir should rise to 1050, the pressure of the vapor in contact with it lbs. and the pressure of the gas in the upper part of the shell 75 would be quite a number of pounds higher. Hence the limit of 220 lbs. is fixed as that at which the high pressure safety device is to act. Assume now that, owing to a failure of condensing water, the pressure in the shell 75 vrises to 220 lbs.

Thereupon the arms 1451A and 1&8 force the arm 153 into contact with'the arm 152 and thereis the same terminationv of the heating of the contents ofthe shell 7 5 as before, except that the percentage of ammonia remaining in the solution is'more or temperature falls, the pressure lthe shell 75.

less greater than in case of a normal termination.

Ineither case, when the heating of the contents of the shell 75 ceases, the temperature in the shell 75 begins to fall. As the rapidly drops, the valve 182 having meantime closed. Vhen the temperature of the contents of the shell 75 has fallen to 110O these are only a few pounds pressure in the shell 75 and it is ready to again act as an absorber. At the low limit of 1100 the arm 14:8 forces the arm 151 into contact with the arm 150. And a current then passes from the wire 10 through the parts 154-, 151, 150, 157, 72 and 158 back to the wire 41. The consequent energization of the solenoid 72 closes theswitch 70 and restores the control of the machine to the refrigerator thermostat. 'Also a branch current from the wire 157 A passes through the parts 178,175, 179 and 180 back tothe wire 41. The consequent energization of thesolevnoid v1.75 draws the core 1,76 to the' right and permits the valve 166 to close. .Consequently the flow of water through the coil 88 is again throttled by the valve 162. The major cycle of operation, involving the heating of the shell 75, is thus complete.

It is evident that, while in one sense the tank vl constitutes a condenser'. yet, in a.

larger sense, the term condenser includes all the conduits through which the refrigerantpasses between the valve 182 andr thev valve 48 and also includes the water conduits associated with these refrigerant conduits. The

broad term evaporator comprehends all the conduits through which the passes between the valve 18 and the valve 93,

refrigerant The term still comprehends,'not merely the shell 75, but in addition the conduits through which the refrigerant passes. between the valve 98 and the valve 182. and also the water conduits leadinfr from the casing 112 through The term thermostat broadly includes all the lconnections whereby it is operative.

that I have invented Aand what I desire to have protected by Letters'Patent is eX` pressed in claims as follows:

I claim: s 1. In combination a condenser. an evaporator leading from said condenser, a still adapted to contain an absorbent and-leading from said evaporatorinto said condenser, means 'for preventing'a back flowbf refrigerant from said condenser into said still and from said still into said evaporator, means for regulating` the expansion of refrigerant from said condenser into said ewiporator and its absorption in said still, and means operating when the pressure in 'said condenser falls to' a .predetermined lim-it to heat said still.

2. In combination a condenser. an evaporator leading from said condenser, a still adapted to contain an absorbent and leading from said evaporator into said condenser, means for preventing a back flow of refrigerant from said condenser into said still and from said still into said evaporator, means for regulating the expansion of refrigerant from said condenser into said evaporator and its absorption in said still, and 'leans controlled by the pressure of refrigerant in said condenser and operating when suoli pressure falls to a piedetermined limit to heat said still to a predetermined limit.

ln eoinbination a condenser, an evaporator leading from said eondenser` a still adapted to eonlain an absorbent and leading from said evaporator into said condenser, means for preventing a back How of refrigerant from said condenser into said still and from said still into said evaporator, means for regulating the expansion of refrigerant fromv said condenser into said evaporator'and its absorption in said still, means operating when the pressure in said condenser falls to a predetermined limit to heat said still normally to one predetermined liinit, and a safety deviee operating to stop such heating in case the pressure in said still, before sueli normal termination, rises above a normal limit.

l. ln combination a condenser, an evaporator leading from said eondenser. a still adapted to contain-an absorbent and leading from said evaporator into said eondeiiser, means for preventingI a baek flow of refrigerant from said condenser into said still and from said still into said evaporator, means for regulating the expansion of refrigerant from said condenser into said `e Yaporator and its absorption in said still,

means controlled by the pressure of refrigerant in said condenser and operating when sueli pressure falls to a predetermined limit to heat said still normally to a high temperature limit'. and a safety deviee operating to stop such heating in ease the pressure in said still in the. time of heating rises above a normal limit.

5. ln eombination a condenser, an evaporator leading from said condenser through a place to be refrigerated, a still adapted to contain an absorbent and leading from said evaporator into said Condenser. means for preventing a back flow of refrigerant from said 'condenser into said still and from said still into said evaporator, dominating means operating when the pressure in said condenser falls to a predetermined limit to heat said still, and refrigerant regulative means temperature controlled in the period 'between the operations of said dominating means and then operative to regulate the expansion of iefrigerantfrom said eondenserinto said evaporator and its absorption in said still so as to maintain a predetermined temperature in said place,

said dominating means during such heating also causing said regnlative means to be inoperative.

(i. In combination a condenser, an evaporator leading from said Condenser through a place to be refrigerated, a still adapted to contain an absorbent and leading from said evaporator into said condenser, means for preventing a back flow of refrigerant from said condenser into said still and from said still into said evaporator, dominating means controlled by the pressure of refrigerant in said condenser and operating when sueh pressure falls to a `predeter- V,

mined limit to heat said still to a predetermined limit, and refrigerant regulative means temperature controlled in the period between the operations of said dominating means and then operative to regulate the expansion of refrigerant from said condenser iiito said evaporator and its absorption in said still so as to maintain a predeterinined temperature in said place, said dominating means during sueh heating also eausing said regulative means to be inoperative.

T. ln combination ay condenser, aii evaporator leading from said (condenser through a place to be refrigerated, a still adapted to eontain an absorbent and leading from said evaporator into said condenser, means for preventing a back flow of refrigerant from said condenser into said still and from said still into said evaporator, dominating means operating when the pressure in said condenser falls to a predetermined limit to heat said still normally to one predetermined limit, a safety device operating to stop sueh heating in ease the pressure in said still, before sueh normal limitation, rises above a normal limit, and refrigerant regulative means temperature controlled in the period between the operations vof said dominating means and then operative to regulate the expansion of refrigerant fromV said condenser into said evaporatorI and its` absorption in said still so as to maintain a predetermined temperature in said place, said dominating means during such heating also causing said regulative means to be inoperative.

S. ln combination a ieondenser, an evaporator leading from said eondenser through a plaee to be refrigerated. a still adapted to contain an absorbent amlleading from said evaporator into said condenser,Y means for preventing a back fiovv/l of refrigerant from said Condenser into said still and from said still into said evaporator, dominating means eontrolled by the pressure of refrigerant in said eondenser and operating when such .pressure falls to a predetermined limit to heat said still normally to a high temperi ture limit, a safety device ope ating to stop such heating in case the pressure in said still in the time of heating rises above a normal limit, and refrigerant regulative means temperature controlled in the period between the operations of said dominating means and then operative to regulate the expansion of refrigerant from said condenserl into said evaporator and its absorption in said, still to said condenser and to said still, and means for utilizing temperature and pressure conditions in said still and condenser to control such heating and cooling operations and to maintain a predetermined temperature in said place.

v10. In combination a condenser, an evaporator leading from said condenser, astill adapted to contain an absorbent and leading from saidl evaporator into said condenser, means for preventing a hack fiow of refrigerant from said condenser into. said stilland from said still into said evaporator,

vmeans for heating at intervals said still,

means for permitting a flow of cooling water at intervals to said condenser and to said still, and means for utilizing temperature and pressure conditions in said still and condenser to control sucliiheating and cooling operations. ,p

l1. In combination a condenser, an evaporator leading from said condenser, a still adapted to contain an absorbent and leading from said evaporator into said condenser,-

means for preventing a back flow of Arefrigerant from said condenser into said still, an automatic expansion valve controlling the inlet end of said evaporator, a stop valve controlling the outflow from said evaporator, and means operative at intervals for closing said stop valve if openl and for heating said still. l

1Q. In combination a condenser,A an evaporator leading from said condenser, a still adapted to contain an absorbent and leading from said evaporator into said condenser, means for preventing a back fiow of refrigerant from said condenser into said still, an automatic expansion valve controlling the inlet end of said evaporator, a stop valve controlling the outflow from saidA evaporator, and means operating when the pressure,

in said condenser falls to a predetermined limit to close said stop valve lif open and to heat said still. 4

13. In combination a condenser, an evaprator leading from said condenser, a still adapted to contain an absorbent and leading from said evaporator into said condenser, means for preventing a back flow of refrigerant fromsaid condenser into said still, an automatic expansion valve controlling the vinlet end of said evaporator, a stop valve controlling the outflow from said evaporator, a thermostat controlled by the temperature about said evaporator and controlling said stop valve, means operative at intervals for closing said stop valve if open, for suspending the operativeness of said thermostat and for starting a. heating of said still, means operative to terminate such heating at a predetermined limit, and means restoring the operativeness of said thermostat after such heating.

14. In combination a condenser, an evaporator leading from said condenser, a still adapted to contain an absorbent and leading from said evaporator into said condenser, means for preventing a back flow of;

refrigerant from said condenser into said,-

still, .an automatic expansion valvel controlling the inlet end of said evaporator, a stop valve controlling the outiiow from said evaporator, a thermostat controlled by the, temperature about said evaporator and controlling said stop valve, means operating when the pressure in said condenser falls to y a predetermined limit to close said stop valve if open, to suspend thev operativeness of said thermostat and to start a heating of said still, means operative to terminate suoli heating at a predetermined limit, and meansv restoring the operativeness of said thermostat after such heating.

`15. In combination a refrigerant reservoir, a still adapted to contain an absorbent. an expansion chamber leading from vsaid reservoir to said still, a conduit `leading from said still to said reservoir, means preventing a back flow of refrigerant from said reservoir into said'still,` means for regulating the flow of refrigerant from said reservoir tliroughsaid chamber` means controlled by the' reduction of the supply of refrigerant in said reservoir to a predetermined limit for starting a-heating of said still,

means vfor terminating such heating,` and in its absorption period.l

1G. In combination a refrigerant reservoir, a still adapted to contain an absorbent, an` expansion chamber leading from said reservoir to said still, a conduit leading from said still to saidreservoir` means pieventing a back floiv of refrigerant from means for cooling the contents of said still said reservoir into said still, means for regulating the flow of refrigerant from said reservoir through said chamber, means conizo - from said still to said reservoir, means preventing a back floiv of refrigerant from said reservoir into said still, valve means for controlling the lion' of refrigerant through said chamber, a thermostat controlllng saidA valve means, means controlled by the re duction of the supply of refrigerant in said reservoir to a predetermined limit for suspending the operativeness of said thermol stat and for starting a heating of said still,

.means for terminating such heating, means foifmaliing said thermostat operative after such heating, and means :for cooling the contents ol said still .in it.' absorption period.

1S'. In" combination a refrigerant reser- .voir, a stilladapted to contain an absorbent,

an expansion chamber leading from said reservoir-.to said still, a conduit leading from said still to said reservoir, means preventing a back liow of refrigerant from saidreservoir into said still, valve means for controlling the flow of refrigerant through said chamber, a thermostat controlling said valve means, means controlled bythe reduction of the supply of refriger ant in said reservoir to a predetermined limitr for suspending the operativeness of said thermostat and for starting a heating of ,said still, means for terminating such heating, means for making said thermostat operative after such 'heating7 means for cooling the refrigerant driven off from said still by such application of heat, and means forcooling the contents of said still in its absorption period.

19. In combination a refrigerant reser voir, a .stilll adapted to contain an absorbent, an expansion chamber leading from said reservoir. to said still, a conduit leading from said still to said reservoir, means preventing' a back flow -of refrigerant .freinsaid reservoir into .said still, valve means for controlling the flow of refrigerant through said chamber, a thermostat con- V.trolling sald valve means, means controlled 'by' the reduction of thesupply of refrigerant in said reservoir to a predetermined limit'for suspending the operativeness of said thermostat and for starting a heating of said still, means for lterminating such heating at a predetermined temperature limit of the contents of said still, means expansion chamber leading from said reservoir to said still, a conduit leading from said still to said reservoir, means preventing a back flow of refrigerant from said reservoir into said still, valve means for controlling the flow lof refrigerantthrough Said chamber, a thermostat controlling said Valve means, means controlled by the reduction of the supply of refrigerant in said reservoir to a predetermined limit for suspending the oiwrativcness of saidthermostat and for starting a heating of said still, means for terminating such heating at a predetermined temperature limit of the contents of said still, means for restoring the operativeness of said thermostat at a lower temperature limit of such contents, means for cooling the refrigerant driven off from said still by such application o'l' heat, and means for cooling the contents of said still in its absorption period.

21. In combination a refrigerant reservoir, a still adapted to contain an absorbent, an expansion chamber leading from said reservoir to said still, a conduit leading from said still to said reservoir, means preventing a back flou' of refrigerant from said reservoir into said still, means for regulating the flow of refrigerant lfrom said reservoir through said chamber, means controlled by the reduction of the supply of refrigerant in said reservoir to a predetermined limit for starting a heating of said still, means for normally terminating such heating, a safety device for operation in case the pressure in said still during such heating` exceeds a predetermined limit to terminate such heating', and means for cooling the contents of said still in its absorption period. l

In combination a refrigerant reservoir, a still adapted to contain an absorbent, an expansion chamber leading from said reservoir to said still. a conduit leading from said still to said reservoir, means preventing a back lo\v of refrigerant from said reservoir into said still, means for regulating the flow of refrigerant from said reservoir through said chamber, means controlled by the reduction of the supply of refrigerant in said reservoir to a predetermined limit for starting a heating of said still, means for normally terminatingsuch heating, asafety device for operation in case the pressure in said still duringsuch heating exceeds a predetermined limit to Vterminate such heating, means for cooling the refrigerant driven off from said still by such application of heat, and means for cooling the contents of said still in its absorption period.

23. In combination a refrigerant reservoir, a still adapted to contain an absorbent,

an expansion chamber leading from said..

voir into said still, valve meansfor conti-oh ling the loiv of refrigerant through said chamber, a thermostat controlling. said valve means, means controlled by the reduction of the supply of refrigerant in said reservoir to a predetermined limit for suspendingthe operativeness of said thermostat vandfor starting a, heating of said still, means for normally terminating such heatingaa safety device for operation in ease the pressure in said still during such heating exceeds a predetermined limit to terminate such heating, means for making said thermostat operative after such heating, and means for cooling the contents of said still in its absorption period.

2l. In combination a refrigerant reservoir, a still adapted tocontain an absorbent,

an expansion chamber leading from said reservoir to said still, a Conduit leading from said still to said reservoir, means preventing a back floiv of refrigerant'from said reser? voir into said still, valve'means for controlling the lioiv of refrigerant through' said chamber, a thermostat controlling said valve means, means controlled the reduction of the supply of refrigerant in said reservoir to a. predetermined limit 4for suspeiid-ing the operativeness of said thermostat vand for starting a heating of said still, means for normally terminating such heating, a safety device vfor operation incase the pressure in said still during such heating exceeds a predetermined liinit to terminate such heating, means for making said thermostat operative Aafter such heating, means for cooling the re frigerant driven off from` said still by such application of heat, and means for cooling the contents of said still in its period.

25. In combination a refrigerant reservoir, a still adapted to contain an absorbent, an expansion chamber leading from said reservoir to said still, a conduit leading from said still to said reservoir, means preventing a back flow of refrigerant from said reservoir into said still, valve means for controlling the flow of refrigerant through said chamber, a thermostat controlling said valve means, means controlled by the reduction of the supply of refrigerant in said reservoir to a predetermined limit for suspending the operativeness of said thermostat and for starting a heating of said still, means for normally terminating such heating at a predetermined temperature limit of the contents of said still, a safety device for operation in case the pressure in said still during such heating exceeds a predetermined limit absorption 'to terminate such heating, means for restoring the operativeness of said tlieimostat at a loiver. temperature limit of such contents, and means for cooling the contents of said still in its` absorption period.

26. Inr combination a refrigerant reser-` voir, a still adapted to contain an absorbent, an expansion chamber leading from said reservoir to said still, a Conduit leading from said still to said reservoir, means preventing a back flow of refrigerant from said reser- .voir into said still, valve means for controlling tlie floiv of refrigerant through said chamber, athermostat controlling said valve means, means controlled by the reduction of the supply of refrigerant in said reservoir Ato av predetermined limit for suspending the operativeness of said thermostat and for starting` a `heating of said still, means for normally terminating such heating at a predetermined -`temperature limit of the ,con-

. tents of said still, a'safety device for operation in case the pressure in said still during 'such heating exceeds a predetermined limit to terminate'such heating, means for restoring'the operativeness of said thermostat at a lowertemperature limit of such contents, means for cooling the refrigerant driven off vfrom said still by such application of heat,

andmeans for cooling the contents of said still in its absorption period.

27. In an absorption refrigerating appaf,

ratas, in combination, a still, a condenser,

4an evaporator, means for connecting said elements to form a circuit from the still throughthe condenser and evaporator back to vthe still, means operative at intervals to heat the stillV and subsequently to' cool the still, temperature controlled 'means operative to regulate the oiv of refrigerant through the evaporator in the intervals betiveen such heatings, and means positioned at the outlet of the evaporator andoperating.

to prevent a fioiv of refrigerant into the still during such heating.

28. In an absorption refrigerating apparatus, in combination, a still, a condenser, an evaporator, meansfor connecting said elements to form a circuit from the still through the condenser and evaporator back to the still, means responsive to a change in conditions in saidy circuit to Iheat the still and 'subsequently to cool the still, temperature controlled means operative to regulate the flow of refrigerant through the evaporator in the intervals between such heatings, and means positioned at the outlet of the evaporator a ud operating to prevent a flow of refrigeriint into the still during such heating.

29. In an absorption refrigerating appa ratus, in combination, a still, a condenser, an evaporator, means for connecting said elements to form a circuit from the still through the condenser and evaporator back to the stille means for utilizing` temperature and pressure conditions in Said Conduit to heat the still and subsequentlyT to Goot the still, tmnperatnre controlled means Opera'- tive to regulate the How of refrigerant through the evaporator in the intervals between such beatings, and means positioned at the outlet of the evaporator and operatingto prevent a flow ot' refrigerant into the still during such heating'.

GEORGE P. CARROLL.Y Titnesses Joux E. PRAGER, FRANK C. HoLRooK. 

